Mind vehicle at end of avenue (4)
I believe the answer is:
care
'mind' is the definition.
(I know that care is a type of mind)
'vehicle at end of avenue' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'at end of' indicates one should take the final letters.
The last letter of 'avenue' is 'e'.
'car'+'e'='CARE'
(Other definitions for care that I've seen before include "Protective custody" , "Have concern or regard" , "Guardianship; anxiety" , "Safekeeping" , "Mind" .)